"Taken together, it seems to me that this is a very important interim development in the Mueller investigation, but only as an appetizer," said Steve Vladeck, CNN legal contributor and professor at the University of Texas Law School.
"And like most meals, if all we get is an appetizer, I think folks on all sides of the political spectrum will find the denouement rather unsatisfying. It's a tantalizing step, but only if it's the first -- and not the last," Vladek said.
All through the political storm whipped up by Russian meddling in last year's election, the White House had insisted there is no evidence of collusion between campaign officials and Russians.
Trump has gone further, branding the whole thing as a "hoax" and a plot dreamed up by Democrats still mourning Hillary Clinton's shock election loss.
And though that narrative was contradicted by assessments of US intelligence agencies, it just about held up as a line of political spin through the early twists of an extraordinary morning in Washington.
Even after former campaign manager Paul Manafort and his sidekick Rick Gates were indicted by the Mueller probe on Monday on serious and sweeping charges of money laundering and tax fraud, the White House still had an opening.
In what passes for good news for this crisis-rocked administration, Manafort and Gates were charged with offenses relating to their business dealings with a former pro-Russia regime in Ukraine, not over activity during the election.
The President pounced.
"Sorry, but this is years ago, before Paul Manafort was part of the Trump campaign. But why aren't Crooked Hillary & the Dems the focus?????" Trump wrote on Twitter. "....Also, there is NO COLLUSION!"
White House sources, meanwhile, coalesced around an argument that expectations of a big break in the case around allegations of collusion between the Trump campaign and Russia were now proven to be misguided.
"Today has zero to do with the White House," a source close to the administration told CNN.
Trump's attorney Jay Sekulow pointed out to CNN's Wolf Blitzer in an interview that that the charges laid against Manafort and Gates pertained to "business activities ... not campaign events."
But Mueller had a surprise up his sleeve -- one that cut deep into Trump's conceit that stories about Russian efforts to forge links with the Trump campaign were simply made up.
An hour after the President's adamant tweet, it emerged that a former foreign policy adviser, George Papadopoulos, had admitted lying to the FBI about contacts
with foreign officials close to the Russian government who discussed "dirt" relating to emails linked to Clinton.
Court papers also describe an email between Trump campaign officials suggesting they were considering acting on Russian invitations to go to Russia.
The indictment does not prove that Trump knew anything about alleged collusion or that the campaign responded to Russian advances. But it is bad news for the White House nonetheless.
For one thing, the Papadopoulos affair contradicts Trump's own assertion that it is now "commonly agreed" that there was no collusion between his campaign and Moscow.
Mueller's pursuit of Papadopoulos shows that the special counsel remains deeply interested in the question -- and could send a chill through other Trump associates and family members embroiled in the Russia drama.
The case against the former foreign policy adviser also stands as the most comprehensive evidence yet put forward by Mueller of an attempt by Russian operatives to insinuate themselves with the Trump campaign.
Given that Papadopoulos has admitted to trying to coordinate with the Russians during the campaign, it becomes harder for the White House to maintain that no one in Trump's orbit was guilty of collusion.
One approach for Trump's defenders is to downplay the importance of Papadopoulos in the Trump campaign.
"George Papadopoulos served on a committee. Campaigns have committees," Sekulow said, adding that his legal liability stemmed from a lie he told an FBI agent, not from any activity during the campaign.
One former senior adviser told CNN's Gloria Borger that the foreign policy expert as a "zero" and a "non-event" in the campaign. But another source told CNN's Jim Acosta that Papadopoulos interacted with the campaign a "significant amount" though was not a familiar face in Trump Tower.
In March 2016, however, Papadopoulos was featured in an Instagram picture posted by the Trump campaign at a meeting between the candidate and a group of foreign policy advisors.
Trump defenders are also likely to say that the meetings pursued by Papadopoulos did not take place. But his activity adds to a previously known pile of evidence detailed meetings between Trump associates, family members and Russians that did take place, and over which people in Trump's orbit had not always been truthful.
While the Papadopoulos revelations appeared to be the most potentially damaging to Trump, the indictments of Manafort and Gates will also leave a scar, notwithstanding the White House dismissal of them.
Trump, after all, was supposed to be the President who would drain the Washington swamp -- but the activities of which Manafort and Gates are accused reek of the insider-ism that Trump has long railed against.
And the fact that the campaign manager who managed his convention is now charged with "crimes against the United States" raises questions about his choice of associates.
Trump's escalating campaign over the last week to discredit the Mueller probe and the deep distrust of the media and Washington authority figures means Mondays revelations are unlikely to harm the President among his closest, most loyal supporters.
But the fact that the Manafort case alone will likely drag on for months -- well into 2018 and possibly beyond -- means that hopes in the White House that the Mueller process could be swiftly dismissed will be unfounded.
The Republican Party itself now faces a midterm election year with the President being continually tainted by the Russia affair and with several of his former high-profile associates potentially facing jail time after a high profile trial.
Democrats did not take long to preview their arguments.
"Paul Manafort and Rick Gates ran Trump's campaign and continued to be a part of his inner circle after Election Day," Democratic National Committee Chairman Tom Perez said in a statement. "This underscores the seriousness of the investigation into Donald Trump's ties to Russia. It's time for Republicans to commit to protecting this investigation and preserving the rule of law."